On Tue, Mar 28, 2023 at 10:21:14PM +0300, Sakari Ailus wrote:
> On Tue, Mar 28, 2023 at 06:44:40PM +0300, Andy Shevchenko wrote:
> > On Tue, Mar 28, 2023 at 01:12:58PM +0300, Sakari Ailus wrote:
...
> > > #define NO_CSI2_PORT (UINT_MAX - 1)
> >
> > Has it been used before this patch?
>
> I don't think so.
>
> It has its current form as you preferred it earlier. :-)
My point is that it needs to be introduced where the first user appears.
> > #define NEXT_PROPERTY(index, max) \
> > (WARN_ON((index) > ACPI_DEVICE_SWNODE_##max) ? \
> > ACPI_DEVICE_SWNODE_##max : (index)++)
> >
> > ?
>
> This appears functionally (almost) equivalent --- it wouldn't overflow.
> I'll use this in v8.
In this form it even takes line less
#define NEXT_PROPERTY(i, m) \
(WARN_ON((i) > ACPI_DEVICE_SWNODE_##m) ? ACPI_DEVICE_SWNODE_##m : (i)++)
...
> > > + ret = fwnode_property_count_u8(mipi_port_fwnode, "mipi-img-lane-polarities");
> > > + if (ret > 0) {
> > > + unsigned int bytes = min_t(unsigned int, ret, sizeof(val));
> > > +
> > > + fwnode_property_read_u8_array(mipi_port_fwnode,
> > > + "mipi-img-lane-polarities",
> > > + val, bytes);
> > > +
> > > + /* Total number of lanes here is clock lane + data lanes */
> > > + if (bytes * BITS_PER_TYPE(u8) >= 1 + num_lanes) {
> > > + unsigned int i;
> > > +
> > > + /* Move polarity bits to the lane polarity u32 array */
> > > + for (i = 0; i < 1 + num_lanes; i++)
> > > + port->lane_polarities[i] =
> > > + (bool)(val[i >> 3] & (1 << (i & 7)));
> >
> > Casting to bool?!
>
> This was the result of our earlier discussion on an earlier version of this
> set.
>
> > Can we read the array and convert it to bitmap, then this voodoo-ish code can
> > be simplified to
> >
> > for_each_set_bit(i, ...)
> > ..._polarities[i] = 1;
>
> for_each_set_bit() operates on unsigned longs (usually u32 or u64) but we
> have u8s here. There's an endianness issue there.
No issue if you convert it to unsigned long:s first.
> > (assuming initially they are 0:s)?
I think open coding the bitmap operations here is not a win.
--
With Best Regards,
Andy Shevchenko
